Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
1
GERDA Detector Mounting
• The Detector Holders
• Detector Handling and Transport Infrastructure
• Clean Room
• Lock System Functionality
• Pogo Pin Contacts
OUTLINE:
Béla MajorovitsMax Planck Institut für Physik,
München, Germany
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
2
GERDA Mission Statement
Popularity of the name GERDA in norway 1880 - 2000
Taken from www.norskenavn.no
2020
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
3
GERDA detector holder: phase I
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
4
GERDA detector holder: phase II
Material balance: •31g Cu,•7g Teflon, •2.5 g Kapton cable
Novel low mass contacting scheme with Cu on Kapton.
Low mass holder is suitable for 20 kg load at LN temperature
I. Abt. et al, NIM A 577(2007)574,
nucl-ex/0701004
Immersing of string into lN without substantial movement within reasonable time
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
5
GERDA detector handling
Minimize risk of damage by touching:
Design allows for touch free transport, mounting and dimounting into test stands and into experiment
Easy to move: just like drinking coffee
Easy to store: just like cooking your goulash
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
6
GERDA Detector Transport
Maximum safety for necessary journeys envisioned Use same system as for most precious thing transported in cars:
System successfully tested: prototype-detector safely transported from Mainz to Munich
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
7
Detector array
Liquid argon
Cryostat (steel + Cu)
Water tank (steel)
Muon veto (Č)
GERDA
Lock systemClean-room
Load detectors from top of the tank through clean room area
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
8
GERDA: the clean room
Class 10.000 clean room
Underneath flow boxes class 100
Detector storage
Test stand
Air shower
Material lock
Mounting station
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
9
Cable Arms
Service Flanges
Space for pumping stations
Circular shutter body
Magnetic transfer arms
The Clean Room and the Lock
Inner lock
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
10
The Lock
Rectangular shutters
Signal Feedthroughs as close to the cable arms as possible.
Outer lock
Magnetic transfer arms
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
11
Detector Integration: Rail system
Magnetic transfer arm
Wheel gear
Cable car
Rail toward outer lock
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
12
Loose pulleysliding on a guiding rail
Cable winch
Overhead pulleyStrain relief
HV and signal cables,Steel cables holding the detectors
Ge-crystals
Side view
Total length between overhead pulley and final crystal position: ~7m
Two steel cables to have a fixed angle position of crystal relative to vertical axis
33mm
Detector Integration: Rail system
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
13
Detector Integration: String Pulley
It is tricky to bring down strings without any torsion--> use torsion resistent guide chain (Kabelschlepp) made of stainless steel
Electrical motor drives the winch
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
14
Towards overhead
pulley
Towards crystal
Contacting Within the Lock
Pogo pin contacts
NiAu plated copper pad surface
Laser welded connection to cables to outside world
Kapton cable towards front end electronics
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
15
Conclusion
• Due to external requirements: very tricky mechanisms
• Technical solutions for all processes exist
• Technical realization well under way
• Only little and only screened materials used (stainless steel and Teflon)
• There will come a time when we can relax and the name GERDA will be popular again
Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9
Béla MajorovitsGERDA detector mounting
16
Phase II storage infrastructure
Pressure gauge
Safety valve
Flow controller to exhaust line
Exhaust line
Flushing line
Towards Pumping line
Detector storage system built at MPI Munich for our prototype detectors.